by Lindsay H. Jones, USA TODAY Sports

by Lindsay H. Jones, USA TODAY Sports

DENVER - NFL Commissioner Roger Goodell conducted a question-and-answer session with fans Saturday before the Denver Broncos hosted the Baltimore Ravens in the divisional round of the AFC playoffs.

About half of the questions from the audience concerned player safety issues, including drug testing, concussion prevention and testing, helmet technology and low blocks that target players' knees.

Goodell said the league is in the process of testing different types of helmets and is continuing to look at ways to make the game safer for players.

"I still believe it comes back to rules," Goodell said.

Later, in an interview with group of reporters, Goodell said rules or practices could be changed to better evaluate players who have suffered non-head injuries during games. Washington Redskins quarterback Robert Griffin III was allowed to return to a wild-card playoff game last Sunday when it appeared he had re-injured his knee and went on to suffer more ligament damage. Griffin underwent reconstructive surgery Wednesday.

"The medical professionals were making the decision. People can argue whether or not it was the right decision, but it was a medical decision, and that's what we want it to be," Goodell said. "Will we make further changes? Yeah, I anticipate we will. We will always look at what more we can do to make sure that the proper medical attention is being given, and they make the best evaluation. It is their determination to make."

Among other items address by Goodell included:

On findings this week that former NFL player Junior Seau suffered from chronic traumatic encephalopathy after his brain was examined: "It's why we're investing in the research, so we can find out more about, about brain injury and disease. Unfortunately there are so many unknowns," Goodell said. "We've been making the changes to the game. We've been making rule changes, making equipment changes. Medicine has a ways to go. We have to fund research - we have that in our collective bargaining agreement to fund $100 million of research - that research is underway, and I think that will be beneficial."

On the field conditions last week at the Redskins' FedEx Field, where both Griffin and Seattle Seahawks defensive end Chris Clemons suffered major knee injuries: "We're going to evaluate that. Interesting enough, we had no complaints about the field from the Dallas game (the previous Sunday)," Goodell said. "So what we have to do is think through that and see what happened between there, and our staff is looking at that to try to determine if the field should be required to be re-sodded, even between the numbers or between the hashmarks. Should that be something we're required to do, especially in these climates? ... A lot of it depends on the climate, the number of events, if any of those events had crummy weather, you know the field can be ruined from that point on."

On the possibility of more outdoor Super Bowls, a subject that resonates in Denver as the city plans a bid for the game: "Football is made to be played in the elements. You see the fans' reaction. They love it," Goodell said, knowing the 2014 Super Bowl will be played at outdoor MetLife Stadium in East Rutherford, N.J. "If it is a success, I think we may see more."

On the future of the Pro Bowl, which generates decent TV ratings but is often plagued by subpar play from players trying to avoid injury: "If we can't improve that, we're not going to play it," Goodell said.

On the possibility of expanding the playoff field from 12 teams to 14 or 16: "It needs to be evaluated carefully. It's got to be special to make the playoffs. It's also got to retain the uniqueness and importance of all the regular-season games," Goodell said. "It has to be done very carefully, if we do it."

Goodell also polled fans at the forum, asking them to raise their hands if they were in favor of an 18-game regular season, a plan that would eliminate two preseason games. About 75% of the approximately 150 people in attendance favored the idea of a regular-season expansion.

The NFL Players Association has repeatedly said players are not in favor of the idea, especially since it seems to be at odds with the league's renewed emphasis on player safety.

"Whatever changes we make, they need to positive, " Goodell said. "We need to make sure they maintain the integrity of the game and make sure that we are keeping the game as safe as possible."